The invention concerns a vehicle seat with a mechanical rocker system, which is spring mounted by means of a pneumatic spring and with an electronic control, which controls air valves for aerating or de-aerating the pneumatic spring as a function of the swing strokes of the rocker system.
Electronic controls for pneumatic seats are known, for example, from DE Auslegeschrift (Examined) 2,736,242 and from DE Patent 3,312,732. They are designed each time for very specific control functions and produce output signals for this purpose, e.g., for switching on an adjusting motor or for monitoring the theoretical middle position of a pneumatic seat by aerating or de-aerating the pneumatic spring. Such controls operate as a function of the swing strokes of the rocker system in that usually two or more sensors sense specific positions, which are travelled over by the rocker system, i.e., given as input signals to the electronic control.
In practice, such controls require a precise adjustment of the sensor, whereby the respective mounting positions of the sensor may be very different on the rocker system, depending on what type of seat or what type of rocker system is used and/or which control function will be carried out with the electronic control. If several control functions will be realized, such as e.g., switching on the air valves for aerating and de-aerating the pneumatic spring and/or connecting or disconnecting an additional air volume, etc., then a corresponding number of sensors must be mounted on the rocker system and adjusted.
The task of the invention is to create a pneumatic-spring mounted vehicle seat with an electronic control, which is mounted essentially in a more simple way with respect to the electronic control, whereby at
the same time several control functions can be realized, without increasing in this way the expenditure for positioning and adjusting the sensors.
This task is resolved by the invention in that the rocker system has one swing stroke sensor, which continually gives off an uninterrupted sequence of electrical signals during the operational state of the seat, which represents a precise analogous-path and time-equal electrical picture of the oscillations of the rocker system, and that the electrical swing pattern is joined to an input of a microprocessor, which compares the swing pattern with preset event theoretical values in constantly recurrent program sequences and if there is a deviation, produces one or more output signals, which control at least the air valves for aerating and de-aerating the pneumatic spring.
According to the instructions of the invention, it is first true that the rocker system is more or less freed of the need for the multiple sensors, which produced discrete input signals (e.g., ON/OFF or voltage YES/NO) for the earlier known seat controls, and for this purpose had to be mounted in the most varied positions of the rocker system and with precise adjustment.
It is now true that a single sensor mounted on the rocker system is sufficient to fulfill all of the requirements of an electronic seat control. The prerequisite is, however, that this single swing stroke sensor continually gives an uninterrupted sequence of electrical signals, which represent an accurate analogous-path and time-equal electrical pattern of the actual swings of the rocker system.
The signal sequences formed by the swing stroke sensor may be present as digital value sequences or as electrical analog signals. The latter are preferably generated by means of a potentiometer, but may alternatively be produced also, e.g., by means of an inductive path sensor or an opto-electronic pickup system, as they are common on the market at the present time.
The swing pattern of the rocker system which is produced electrically is placed at the input of the microprocessor according to the instructions of the invention. Thus it is of advantage that on the one hand, the processor may be arranged anywhere on the seat or remote from the seat and does not cover the constricted space within the rocker system; on the other hand, however, it has available at its input a complete and time-equal electrical swing pattern of the rocker system.
With this electrical swing pattern, the processor may question, corresponding to its operational cycle, i.e., in constantly recurrent program sequences, specific swing actual values by comparison with preset event theoretical values, whereby the preset or preadjustable event theoretical values may be changed according to a particular form of embodiment of the invention. This is an essential advantage, since now many event actual values of the oscillations of the rocker system can be detected at random, without the need for mechanical arrangement or mechanical change nor the adjustment of individual sensors on the rocker system for this purpose. The rocker system does not need a multiple arrangement of individual sensors, as this was previously known in the case of electronic controls for detecting diverse distinguishable input signals. The seat control of the invention can be correspondingly adapted simply and without problem to the respective type of seat or the respective rocker system.
Thus it is of advantage to be able to change the technical circuit processing of the event actual values within the processor questioned from the electrical swing pattern in order to adapt the control to the respective type of seat or for generating specific output signals, since this can be done by means of memory-programmable processors.
In modern seat construction, it is known that the swing behavior of the seat can be changed not only by aerating or de-aerating the pneumatic spring, but for this purpose, also, a so-called additional air volume can be added or again disconnected from the latter. Likewise it is known how to connect or disconnect an auxiliary shock absorber to more intensely attenuate the swings of the seat in case of need. The expenditure for the control of such additional elements, however, was previously correspondingly high. Now it is shown how such additional elements can be simply controlled according to the instructions of the invention.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.